How many miles have you traveled at 88mph in half an hour?

2. A Formula One race car speeds up from rest to 27.8 m/s in a distance of 25 meters.

Nadya [2.5K]

Answer:

Correct answer: a = 15.46 m/s²

Explanation:

The formula for accelerated movement with the given data is:

V² - V₀² = 2 · a · d where the initial velocity V₀ and the final V

Since the initial velocity V₀ is zero, the formula is:

V² = 2 · a · d => a = V² / (2 · d) = 27.8² / (2 · 25) = 772.84 / 50 = 15.46 m/s²

a = 15.46 m/s²

God is with you!!!

4 0

3 years ago

What was the most serious money problem faced by people in the early United States?

alexira [117]

♥B. There was no single medium of exchange.♥
Take a look at the saying "Not worth a Continental".
It referrers to the fact that currency issued by the Continental Congress was usually just a promise to pay.
Leaving your answer with ♥B♥

5 0

3 years ago

Which property helps to explain differences in the specific heat capacities of

tatyana61 [14]

Answer:

D. Forces between molecules

Explanation:

Specific heat capacity of water can be defined as the amount of heat a gram of water must lose or absorb in order to change its temperature by a degree Celsius. It is measured in Joules per kilogram per degree Celsius (J/kg°C). Generally, the specific heat capacity of water is 4.182J/kg°C and is the highest among liquids.

Mathematically, the specific heat capacity of a substance is given by the formula;

$c = \frac {Q}{mdt}$

Where;

Q represents the heat capacity or quantity of heat.

m represents the mass of an object.

c represents the specific heat capacity of water.

dt represents the change in temperature.

Cohesion is a property of water and it typically refers to the attraction between molecules of water which holds them together.

In Science, the property which helps to explain differences in the specific heat capacities of two substances is the forces between molecules.

This ultimately implies that, the more closely bonded the atoms of a substance are, the higher or greater would be the substance's specific heat capacity. Thus, it varies for the various states of matter i.e solid, liquid and gas.

4 0

3 years ago

Describe the 3 main components of work.

nadezda [96]

Work is Force x Distance in the Direction of the force.

3 0

3 years ago

When a metal rod is heated, its resistance changes both because of a change in resistivity and because of a change in the length

monitta

Answer:

$3.34\Omega$

Explanation:

The resistance of a metal rod is given by

$R=\frac{\rho L}{A}$

where

$\rho$ is the resistivity

L is the length of the rod

A is the cross-sectional area

The resistivity changes with the temperature as:

$\rho(T)=\rho_0 (1+\alpha (T-T_0))$

where in this case:

$\rho_0$ is the resistivity of silver at $T_0=21.0^{\circ}C$

$\alpha=6.1\cdot 10^{-3} ^{\circ}C^{-1}$ is the temperature coefficient for silver

$T=180.0^{\circ}C$ is the current temperature

Substituting,

$\rho(180^{\circ}C)=\rho_0 (1+6.1\cdot 10^{-3}(180-21))=1.970\rho_0$

The length of the rod changes as

$L(T)=L_0 (1+\alpha_L(T-T_0))$

where:

$L_0$ is the initial length at $21.0^{\circ}C$

$\alpha_L = 18\cdot 10^{-6} ^{\circ}C^{-1}$ is the coefficient of linear expansion

Substituting,

$L(180^{\circ}C)=L_0(1+18\cdot 10^{-6}(180-21))=1.00286L_0$

The cross-sectional area of the rod changes as

$A(T)=A_0(1+2\alpha_L(T-T_0))$

So, substituting,

$A(180^{\circ}C)=A_0(1+2\cdot 18\cdot 10^{-6}(180-21))=1.00572A_0$

Therefore, if the initial resistance at 21.0°C is

$R_0 = \frac{\rho_0 L_0}{A_0}=1.70\Omega$

Then the resistance at 180.0°C is:

$R(180^{\circ}C)=\frac{\rho(180)L(180)}{A(180)}=\frac{(1.970\rho_0)(1.00285L_0)}{1.00572A_0}=1.9644\frac{\rho_0 L_0}{A_0}=1.9644 R_0=\\=(1.9644)(1.70\Omega)=3.34\Omega$

7 0

3 years ago